Desulfurizing lima or analogous petroleum and related oils.



UNITED STATES PATENT OFFICE.

CLARENCE I. ROBINSON, OF WEST NEW BRIGHTONQNEW YORK, ASSIGNOR TOSTANDARD OIL COMPANY, OF BAYONNE, NEW JERSEY; .A. CORPORATION OF NEWJERSEY.

DESULFU'BIZING LIMA OR AN ALOGOU'S PETROLEUM AND RELATED OILS.

Specification of Letters Patent.

Patented. 59.11.26, 1909.

Application filed April 5, 1906. Serial No. 310,080.

To all whom 'it may concern:

Be it known that I, CLARENCE I. ROBIN- soN, a citizen of the UnitedStates, residing 'at West New Brighton, in the county of Richmond and'State of New York, have invented new and useful Improvements inDesulfurizing Lima or Analogous Petroleum and Related Oils, of which thefollowing is a specification.

This invention relates to the removal of sulfur from etroleum similar tothat produced (that 1s, obtained from Wells) in the neighborhood ofLima, Ohio, and in the State of Indiana, and from other etroleumanalogous thereto in the particu ars hereinafter set forth, and-alsofrom certain-related oils as hereinafter set forth; andit has moreparticular reference to the desulfuration of Lima petroleum in the formof burning oil (kerosene) distillate, that -is to say, in the form ofany distillate which is mainly or wholly composed-of hydrocarbons properfor burning oil (kerosene).

4 By means of said invention, with use of the ordinary stills andagitators to be found generally in oil refineries and of a cooler suchas is not uncommon therein, one can make from Lima petroleum aburningoil (kerosene) of a low content of sulfur, not exceeding the.percentage of sulfur contained in burning oil (kerosene) of similargrade from said petrolcum heretofore made and marketed; and it isbelieved that such burning oil (kerosene) can be so made at asufliciently low cost to be financially rofitable.

" The etroleum roduced in the neighborhood 0 Lima, Ohio, and in theState of Indiana, and other petroleum similar'thereto, is herein-calledLima oil or Lima petroleum for convenience of reference and asindicating oneplace' of roduction, but not as restricting the pronotion-to such locality; The

petroleum, for example, which is produced 111- the province of Ontario,Canada, is Lima oil for the purposes of this specification;

because it is considered tobe of a nature Indiana.

The said invention, however, re ates to the desulfuration of Lima notonly analogous, but also substantially similar, to that roduced in theneighborhood of Lima, bio, and in the State of For the purposes of thisspecification such similarity of nature is sufii- .ciently shown for anpetroleum by the fact that in the form 0 that distillate which distilsover between 300 F- and 550 F. from the, oil in its'crude state andwhich consequently'can be taken as fairly representing its uncrackedburning oil (kerosene) fraction as a whole it responds to all four ofthe undermentioned tests, after it has been prepared therefor bytreating it in the form of its said distillate with sulfuric acid andalkali (using sulfuric acid of about 300 F. are rejected, and thosewhich come" over subse uently are collected in one receiver until thethermometer attains a temperature of 550 F., when the re uireddistlllate will have been collected. hereupon 'the distillation isstopped or the receiver changed. To prepare this distillate for testing,it can be treated with sulfuric acid and alkali in a glass separator(say, the pear-shaped separator in common use in the laboratory).

The following are the four tests referred to above, to each of whichLima oil in the form of its said distillate, after being prepared fortesting as aforesaid, responds, namely:

First. When tested by a refractometer, it exhibits a refractive indexsufficiently less than 1.4600 to indicate a non-smoking oil. An oil witha refractive index of 1.4600 is to be considered smoky. An oil with arefractive index of 1.4545 is to be considered nonsmoking.

Second.v It turns lumbate of sodium formed by dissolving lit large tosaturation in caustic soda lye.

Third. It has a sulfur content of more than one-tenth of one per cent.

Fourth. Upon treating one 'quart of the prepared distillate by.agitation for a few drawing off the sludge, and was ing wit water,caustic soda lye, and again with water,- the portion which has so beentreated with the acid of about 66 B. will be found to have a lar ersulfur content than will the portion whic has been treated with the 98%acid; and the difference will be suifi'cient to indicatea usefuldesulfuration of the said distillate by the 98% acid over andabove thedc sulfuration of the same(ifany) effected by" an equal amount of acidof-about 66 B. i In other w ords, Lima oil in the form of-its saiddistillate prepared as aforesaid contains sulfur compounds unrernoved bysulfuric acid 'of about 66 B. which are removable'to a useful extent bysulfuric acid of about 98%.

Any etroleum which in the form of distillateyi'e ded between 300 F. and550 F. by

- the crude oil under the'aforesaid conditions responds, after the)described preparation thereof in said form,.to all four of these teststherein at such time might material is Lima oil or Limapetroleum for thepur-' poses of this specifications 4 The 'preparato'ry treatment is imortant, because it removes the hydrogen, su d and other "easilyremovable sulfur compounds which might otherwise be resentin the oil atthe time .of testing an whose presence y a e the tests. -Th,us hydrogensulfid'would give a brown or black coloration with the plumbateof sodiumsolution; and this coloration would more or less obscure and mi htwholly obscure a yellow color develo ed also by said solution. There arealso su fur compounds which are removed by said preparatory treatmentand which would give a yellow colora-' tion with said solution, if theywere present .in the oil at the time ofapplying the'tests.

The hydrogen sulfid and other easily remov- .able sulfur compoundswouldincrease the sulfur content of oil containing" the same and mightgive the sulfur percentage of the third test in a case where otherwiseit would. be less than said-test re uires. Were the to be present in theoil w en it is subjecte to the fourth test, they would be removed by thesulfuric acid of about 66 B. of this test, aswell as by the 98% acid;and consequently they would tend to obscure the difference inresistanceto removal exhibited by the more characteristicsulfurcompounds of Lima oil towards sulfuric acid of about 66 B. andtowards 9 8% sulfuric 'acid, respectively. Ac-

ro-. f

distillate, prepared .as aforesaid, has had arefractive index of about1.4400; (2) has con--' tained not less than 2/ 10' per cent. of sulfur;

(3) has turned -a pronounced canary yellow on addition of the sodiumplumbate solution thereto, and (4) has had its sulfur content reducedfrom 225/1000 "per cent. to about. or

below 1110 per cent. by the specified proportion of 98% sulfuric acid,whereas another portion of the same'prepared distillate had a sulfurcontent of more'than' 2/10 per cent.

after it .had beenv treated with thes'aid proportion of sulfuric-acid ofabout 66 In settingrforth the fourth test above ref- 'erence' is-made toa certain proportion. of ac1d to 011, not because ad1fierent1al-res1starms is exhibited only with such proportion, but inorder to state thetest more definitely and bythe use of a largeproportion of the respective acids to show the stability of thesulfurcoinpounds of Lima oil against removal bysulfliric acid of about66 B. The

tests may befmadeat any suitable temperature, say, at about 60 F. or atthe actualtemperature of the roomin which the tests maybe performed,whether above or below In the fourth test reference is made to nonfumingsulfuric acidv .of about 98% sulfuric monohydrate, [not because it isthe only sulfu'ric acid which is able to remove sulfurcompounds of Limaetroleum which are not'.

removed by an e ,ua Weight of sulfuricacid of about 66 5.; "ut by way ofexample and also because it is considered "the most advantageous form ofsulfuric acid stronger than. that of about 66 B. to be used incarryingthe present invention into efl ect. My ex erience leads me to concludethat from a out 98% sulfuric monohydrateiupward the desulfurizing actionof sulfuric ac1d on Lima oil increases gradually with the acid strength,bein somewhat greater for sulfuric nionohy rate (100%). than for 98%acid and still reater forfuming sulfuric acid, and that rom about 98% ownward the desulfurizing action. of sulfuric acidon: Lima oildiminishes, at firstgradually; and then in increasing degree (beingmaterially smaller for 96% acid than for 98% ac1d and be.taken tocontain, from 925% to 93% s 'furic monohydrate. Sulfuric acid .of about98%;is a commercial article and is produci ble either by off the waterfrom higher ratio of desulfurizing action to cost than acid which is notso strong (and hence -.not so high in desulfurizing action, althoughslightly 'chea er) or-than still stronger acid (which is er in cost,although also somewhat higher in desulfurizing action). 1

In making burning oil (kerosene) it is customary to treat the burningoil (kerosene) distillate with sulfuric acid of about 66 B. at about 601}. initial; that is to sa burning oil (kerosene) distillate isordinar'y cooled or heated, as the case may require, to

bring it to about 60 F. (cooled in summer and heated in winter); and theacid is then i added to the oil at about 60 F. in the agitator. The acidis added at the temerature which it happens to have. The aci and oil areagitated with a blast of air having usually the existing atmospherictemperature. During the agitation the temperature usually rises, say,about 10 F'.,'in conse uence of the heat develo ed by the chemicareaction of the acid on t e oil.

-It is possible to desulfurize Lima petroleum'in'the form of burning oil(kerosene) distillate to the extent necessary '-to give a marketableburning oil (kerosene). by treating such distillate at about 60 F.initial with-sulfuric acid of about 98% sulfuric acid or with othersulfuric acid .a ropriately stronger than that of about 66 B; but to doso a large pro ortion of such stronger acid is needed 111 or er toaliord a sufiicient reductioh in sulfur content For example, as-

' sume (as would be possible and as I have, in

-fact, experienced.) that crude oil from the neighborhood of Lima, Ohio,or from the State of Indiana, should be distilledand that an unc'rackedburning oil (kerosene) distillate should be collected as the stock to betreat ed and that it should constitute all the distillate received fromthe beginning of distillation of said crude oil until the distillatefrom the tail pipe of the condenser has a. gravity of about 41 B. andthat it should amount in volume to fifty per cent. of the crude oil. (inother Words, that the volume of collected distillate should be equal tothe volume of the undistilled portionfof the crude oil), and that itshould contain an amount of naphtha equal to about eleven per cent. ofthe crude oil, and that said stock (as ob tained directly from thecondenser) should show a sulfur content of three hundred 'and fortysix-one-thousandths of one per cent. (a not uncommon percentage for sucha cut of. distillate). To treat this stock (hereinafter referred to asthe abovementioned-uncrackedstock) at about 60 F. initial with 98%sulfuric acid in such manner as eventually to obtain burning oil(kerosene) containing not rel). The stock, after the treatment with 98%acid, may contain about one-tenth of one'per cent. of sulfur; but thisercentage can, in my experience, be reduce to or 'below one-twentleth ofone per cent. by rerunning (that is, by distilling the treateddistillate) and giving the rerun oil .a light treatment with sulfuricacid and alkali, using,

say, three or four pounds of sulfuric acid of 1 about 66 'B. to eachbarrel of rerun distillate, or the samefproportion of acid sludge fromthe treatment with 9 8% acid, and finally steam stilling to drive offthe naphtha and so to give'burning oil (kerosene) of suitable'fire test.The steam stilling, it may be observed, increases somewhat the sulfurcontent, because the expelled naphtha holds a less percentage of sulfurthan the residual burning oil (kerosene) does.

If the-above mentioned uncracked stock should be treated preliminarilywith sulfuric acid and alkali,,using twenty pounds of sulfuric acid ofabout 66 B. to the barrel of stock; and if the so treated stock shouldthen be treated at about 60 F. initial with 98% acid, using betweenforty and fifty pounds to the barrel, and be followed by rerunning andsubsequent 'li ht treatment with sulfuric acid and alkai and steamstilling, the finished burning oil (kerosene) so obtained ceedingone-twentieth of one per ce t. After the reliminary treatment (that is,with acid of-a out 66 B.) the sulfur content'may be about two hundredand twenty five onethousandths per cent., and after the maindesulfuration (that is, with 98% acid) about one-tenth per cent. Some98% acid would be saved by the reliminary treatment, but not, it isbelievefl, sufficient to counterbalance the cost of the acid of about 66B.

With or without the preliminary treatment, the quantity'of sulfuric acidneededto give a marketable burning oil (kerosene)- would be so large asto be a serious objection to an industrial manufacture, if notprohibitive thereof, especially in view of the other necessary expensesof refinin To use other sulfuric acid' substantiall stronger than acidof about 66 B., in place of 98% acid, would notmeet the difficulty; forthe ratio of cost to desulfurizing action is prob-' ably least in thecase of 98% acid; and, if it were not so, so large a proportion of acidin any case would be needed that its cost would prove a serious (if nota financially fatal) obshould likewise have a sulfur cont t nbt ex-'jeetionr Moreover, the large proportion of acid stronger than that ofabout 66 B.

would in any case destroy a considerable --,amount of hydrocarbons whichotherwise "would be useful constituents of the burning oil (kerosene)and would probably also prove injurious to the color of the oil, evenafter 3 lieve by me (a) that by operating on Lima oil in the form ofburning oil (kerosene) distillate at about or below 38 F. initial asufficient desulfuration to give a marketable burning oil (kerosene)'can be effected with only about a third of the 98% sulfuric acid (or ofother sulfuric acid appropriately stronger than that of about 66 B.)needed to effect the same desulfuration of the same quantity of the samestock at about 60 initial; (6) that by operating at temperatures betweenabout 38 F. initial and about 60 F. initial an equal desulfuration deamands more and more acid until a temperature is reached atwhich'substantially the same proportion of 98% sulfuric acid or othersulfuric acid stronger than that ofabout 66 B. is neededas would berequired at about 60 F. initial; (0) that the increase in acid demandedfor a given rise in temperature above about 38 F. initial becomes largerand lar er as 56 F. initial is approached, so t at the differencebetween about 38 initial and'about 44 F. initial is not so great asbetween about 44 F. initial and 'about F. initial, and this in turn notso. great as between about 50 F. initial and about 56 F. initial,-. and(d) that'the amount of desulfuration at about or below 38 F. initial andat any temperature between the same and about 60 F. initial can beincreased or decreased by using a lar er or asmaller roportion of 98%sulfuric aci( orof other su uric acid s tro'n er than that of about 66B., although I elieve that for a given stock and a given stronger acidthere is an irreducible minimum, or, in other 1 words, a certain sulfurcontent which cannot substantially be reduced. by using an increasedproportion of the acid.

By treating the above mentioned un- I. cracked stock 'with 98% sulfuricacid at about 38 F. initial, followed by rerunning, by a subsequentlight treatmentwith sulfuric acid and alkali, and by steam stilling, Ihave obtained finished burning oil (kerosene) with not exceeding 1/20per cent. of sulfur,

by using the 98% acid at the rate of twenty pounds of the same to thebarrel of stocktreated. The following table shows, by way of .example,the sulfur contents of finished burning oil (kerosene) which I haveobtained by the above procedure, using different strengths of sulfuricacids stronger than that of about 66 B. on different samples of theabove mentioned uncracked stock at the rate of twenty pounds to thebarrel, namely:

95% acid gave 5 -/1000 per centasulfur.

sulfur. sulfur. sulfur.

' 96% acid" gave -5'5/1000 per cent. 98% acid gave -50/1000 per cent.100% acid gave 110/1000 per cent. Fumingaci (10 per ct. anhydrid) gave45/1000 per cent. Sulfuric anhydrid gave -40/1000 per cent. sulfur.

By using more. than twenty pounds of the 98% acid or other acid strongerthan that of about 66 B. to the gallon of stock the sulfur content ofthe finished burning oil (kerosene) sulfur.

can be further reduced, until the irreducible minimum is attained. Thislatter will be higher or lower for the above mentioned uncracked stock,according to the particular same reason, if an oilwith asulfur contentof 75/1000 per cent. should be satisfactory, it would be moreadvantageous to use 98% acid. The use of acid less strong than that ofabout 98%, or even than that of about 95% is not excluded from theinvention; but its use is considered not so advantageous as the use ofacid of about 98% {and cases may arise for which the less strong acid,or even 98% acid, would be available for part only of the desired,desulfuration on account of the minimum ercentage of sulfur obtainabletherewith eing higher than that desired. The use of sulfuric acidstronger than that of about 98%is also included in the invention.

Where 98% or other extra strong acid is hereinafter referred to, theexpression Wlll be understood to include not only non-fumingappropriately stronger than that of about 66 13., whether stron er thanor not so strong as non-fuming sulfuric acid of about 98% sulfuricmonohydrate'.

With the same initial temperature of treatment, the sulfur content ofthe finished burning oil (kerosene) depends not only on the articularstrength and proportion used of tie 98% or other extra strong acid, but

also on the boiling points and percentages of' the. differenthydrocarbons composing the stock, uponthe s'ul'furc-ontent of suchstock, and upon the character of the stock as composed greater or lessproportion of cracked products or as consisting substantially of dis-.tillate obtained without cracking; and if the stock should be more orless desulfurized (as it may within the limits of the invention be more.or less desulfurized) before or after treatment with 98% or other extrastrong acid, the sulfur content would also depend upon theextent andcharacter of such prior or subsequent desulfuration. In a general way,according to my experience, inorder to obtain burning oil (kerosene) ofa given attainable sulfur content, the pro ortion of the 98% or otherextra strong aci must be increased with increase in the average boilingpoint of the hydrocarbons composing the stock to be treated therewith,also with increase in the sulfur content of such stock before thetreatment, and with increase in the proportion ofcracked-products insuch stock; and it may .be diminished with decrease in each of theserespects. When a prior or a subsequent desulfuration by other means isto be resorted to, the treatmentwith 98% or other extra strong acid iscarried on with a proportion of such acid adapted to the desulfurationto be performed by it.

To adjust usefully the pro ortion of 98% or other extra strong acid to te different conditions liable to be encountered in practice, it is notnecessary to possess a mathematical formula. The invention does notconsist in any particular mode of effecting such adjustment; but, by wayof example, it may be observed that one available mode wouldconsist intaking a small quantity (say enou h to fill an agitator to the usualheight) of the burning oil (kerosene) distillate of Whatever kind,treating it at about 38 F. initial with 98% or other extra strong acidat the rate strong acid in the proportion of five pounds of ofrerunning, the oil would best also be rerun said acid to the barrel ofsaid roduct, until either a satisfactorily low sul ur content isobtained, or it is seen that an irreducible mimimum has been reached, ort at cost of further acid would give a financially pro-' hibitive total.After the treatment with each lot of acid at the five pounds to thebarrel rate, the acid sludge would best be drawn off before the next lotof acid is applied; and,

unless the oil refiner should be sufficiently experienced accurately toforecast the effect and subse uently given a light treatment withsulfuric acid and alkali before such ap;

- plicatijon. With the same cut or cuts from the same Lima crude oil,the same propor tion of 98%. orother extra strong acid may beexpected'to give burning oil (kerosene) of the same sulfur content. a

According to my experience, there is no advantage," or at leastnonecommensurate -with the. increased cost of cooling, inreducxmg the'mitialtemperature of the stock below about 38 F. although much the samedesulfu'rizing efl'ect per pound of 98% or other extra strong acid canbe obtained at lower temperatures; The following table showsthe poundsof 98% sulfuric acid to the barrel of stockwhich I have found-to beneeded to make a finished burning oil (kerosene) of. 1/20 er cent.sulfur from the abovementione uncracked stock by treating it with saidacid at different tem eratu'res at about and above 38 F. initia and thenrerunning the so treated stock and-givmgthe rerun distillate a li httreatment with sulfuric acid and a1kal1,-followed by steam stilling toremove the na htha,

namely:

At about 38 F= initial- 20 pounds. Atabout 44 F. initiaL 25.pounds.

At about 50 F. initial- 37 pounds. At about 56 F. initial- 54 pounds.

. The explanation of the ability of a smaller pro ortion of 98% or otherextra strong aci when applied to Lima oil at about or below 38 F. or atother temperature substantially below'about 60 F. initial, to accomplishthe same, desulfurizing effect as a larger proportion of the same acid,when applied to the same stock' at about 60 F. initial or at any lowertemperature which is yet above-38 F. and also abowe that at which thesmaller pro ortion of acid is used, consists in the fact as I believe)that the affinity of 98% or other extra strong acid for the sulfurcompounds of Lima oil is diminished by such decrease in temperature lessthan its atfinity for the unsulfured hydrocarbons of Lima oil isdiminished thereby. The chemical energy of the 98% or other extra strongacid expends; itself, I believe, at all the temperatures botk upon thesaid sulfured and the unsulfured com ounds; but the ratio in which itacts upon them, respectively, is dif ferent at the differenttemperatures; and'the larger proportionate expenditure is upon thesulfur com ounds at the lower temperatures herein a bove set forth. But,whatever the explanation, an e ual desulfurizin effect is produced by asma er proportion 0 .acid at said lower tem erature; and there is lessdestruction of use 1 unsulfured hydrocarbons by' the smaller proportionof the desulfurizing acid and also less injury any) by'it to the colorof the oil after rerunmng.

'The burning oil (kerosene) distillate from Lima crude oilto bedesulfurized in accordance with this first part of the presentinventionmay include-all or any part of the In desulfurizing the above mentioneduncracked stock in themanner above set forth, the naphtha driven off inthe steam stilling I should have a sulfur content not exceeding 1/100 ofone per cent. A naphtha out can also be desulfurized' apart from theburning oil (kerosene) hydrocarbons; although itis.

' considered ordinarily moreadvantageous to I desulfurize them togetherand afterwards to separate the desulfurized naphtha from thedesulfurizedburning oil (kerosene). e

The second part of the present invention is based upon the discoveryfirst made I believe by me (a) that in desulfurizing Lima oil in theform of cracked oil with 98% or other extra strong acid, a burning 'oil(kerosene) of lower sulfur content (within the limits attainable withthe particular stren th of acid employed) can be made by desul rizingthe heavy end ofthe burnin oil (kerosene) fraction of a given cracked oiapart from the light end thereof than'can be made by desulfurizing thesaid light and heavy ends together b means, of an equal ro ortlon of 98or ot or extra strong acid,

an (6) that by treating the heavy end of the burning oil (kerosene).fraction of Lima cracked oil apart from the light end thereof 40 with98% or other extra strong acid, said heavy end can be obtained with asulfur content substantially lower than the minimum heretoforeobtainable (as I believe) from the Limacracked oil of the same originalsulfur content, by means of any prior process of desulfuri g Limapetroleum at like (or even at any) cost.

The discoveries which form the basis-of this second part of the presentinvention are best made available by employing the 9.8 70 or other extrastrong acid at temperatures below about 60 F. initial as above setforth, on account of the saving of. acid and oil and the avoidance ofinjury to the color of the oil, andsuch treatment is specially claimed;but the application of these discoveries is not necessarily confinedwholly'to the use of'the 98 or other extra strong acid at such lowertemperatures; for there 1s a saving of acid by treating: the heavy endseparate -from the light end, even" at about 60 F.

initial (and I believe at even higher temperatures, if it should bedesired for any reason to employ a higher temperature) as compared witha treatmentat thesame tem ong with all.

- during perature of the said heavy end in admixture with said lightend; and I believe that by such separate treatment, even at about orabove 60 F. initial, it is possible to obtain said .heavy end of a lowersulfur content than has been attainable hertofore. The abilityprofitably to securethe hydrocarbons which compose the heavy end of theburning oil (kerosene) fraction of Lima cracked oil with a lower sulfurcontent than the -minimum heretofore attainable at like cost (if at all)gives to such hydrocarbons a substantially increased value asconstituents of burning oil (kerosene) where the lowest sulfur contenthigh as to inter ere with the fitnessof' said hydrocarbons to ,serve assuch constituents.

Thus, for example, in my experience, the cracked oil from the same Limacrude petroleu-m from which I have obtained the above mentioneduncracked stock has yielded a light and a heavy end of the. followingrespective descri tions, when said cracked oil was itself distilled inthe ordinary way, namely:

a light end of the burning oil (kerosene) fraction equal in volume toabout eight per cent. of the'crude' oil and containing an amount ofnaphtha equal to about one per cent.- of the crude oil and having agravity of 49 B. 'and asulfur content of two hundred and thirty sixone-thousandths per cent., and a heavy end of the same fraction equal involume to about twelve and a half per cent. ofthe crude oil and having aravity of 37 4/10 B'. and a sulfur content 0 three hundred one-thou- 1sandt-hs er cent., the receiver being changed tlie distillation when thegravity of the, Oll from the tail. pipe of the condenser reached 43 13.,and the collection of said heavy end stop ed when the gravity of oiltherefrom reao ed 35 B. A mixture of some of the light and heavy endswith each therin proportion to their respective volumes as collected, soas to give a third stock representing the distillate which would be 7obtained by collecting both light and heavy ends in the same receiver,had .a gravity of 4 1 2 10 B. and a sulfur content of two hundred andseventy: one-thousandths per cent. It, of course, represented abouttwenty and a 1 half per cent. of the crude oil and contained naphthaequal to about one per cent. of the crude oil.- By separate treatment ofeach of these three cracked stocks with 98 sulfuric acid at therateofftwenty pounds to the barrel and at a temperature of about 38 Finitial, followed in the cases of the light and heavy ends by. se 'aratererunning, and subsequent separate light treatment with sulfuric acidand alkali, and in the case of the mixed stock by rerunm'ng with changeof re ceiver when the distillate from the tail ipe of. the condenserreached 43 'B-.'-and su sequent light treatment of the so collectedlight and heavy ends separately withsulfuric acid 1! reviouslyattainable is so 80 and alkali, and also followed in the case of the.two light ends by steam stilling to the same extent, I have obtainedproducts with sulfur contents as under, namelyz' The increaseddesulfurizing effect due to the desulfuration of the heavy endseparately from the light end is apparent.

By treating the three cracked stock separately at about 38 F. initialwith a larger proportion of 98% sulfuric acid, namely in the proportionof thirty pounds to the barrel,

followed in each case by the corresponding procedure as set forth above,I have obtained heavy endof still lower percentage of sulfur as follows:

Concurrently desulfurized light end 52/1000 per cent. Concurrentlydesulfurized 'heavy end 123/1000 per cent. Se arately desu l f u ri z'ed ight end 48/1000 percent. Se arately desulfurized I lieavy end 90/1000per cent.

I d-o'not believe that the heavy end ofethe same Lima cracked oil isobtainable by any prior rocess of lower sulfur content than that givenin the last table above for concurrently desulfurized heavy end," ifindeed it can be so obtained of as low acontent of sul-f fur. Th stilllower sulfur content .of the separate y treated heavy end can be seen'on inspection of this table; and it is to be noted that no additionalacid has been needed to obtain this lower sulfur content,

The third part of the present invention is based upon the discoveryfirst made I believe by me that 'inthe heavy end of the burning oil(kerosene) fraction of Lima cracked oil there are present sulfur com-vpounds which are unremoved not only by sulfuric acid of about 66 B., but"also by some at least of the materials (other than 98% or-other extrastrong acid) heretofore .employed or proposed as desulfurizers of Limapetroleum and having on the latter a more energetic desulfurizing actionthat is" possessed by sulfuric acid of about 66 B., but which compoundsare, nevertheless, removable by means of 98% or other extra strong acid.And I believe that when Lima cracked oil is desulfurized, under whateverconditions, by, materials which have been *heretofore used or proposedas desulfurizersof Lima oil (including various metals, metallic oxids,metallic salts, and non-metallic desulfurizing agents) other I than 98%or other extra strong acid, it retains in its heavy end sulfur compoundsremovable by 98% or other extra strong acid; although it may be thatexceptions exist.- InaccOrdance with this third'part of the'inventionthe heavy :spect to its sulfur content is] effected by means of 98% orother extra strong acid. In either or in each desulfuration the saidheavy. end can be subjected to the desulfurizing agent either inconnection with or apart from t plied to the oil at about 60F. 'or atother preferred temperature; but it is considered more advantageous anda special improve ment to subject the heavy end to the 98% or otherstrong acid apart from the light end, and also to subject thesamethereto at temabove. V

gLima cracked 011 in general, even in the lighter end of the burning oil(kerosene) fraction, is improved in its sulfur content by, subjection to98% or other extra strong acid after it has been desulfurized by someother material, say cop er oxid, whic is more en ergptic ,as a de'sufurizer of Lima oil than is su uric acid of about 66 3.; and it may insome-cases be advisable to subject Lima oil in other forms than that ofcracked oil to such subsequent treatment with 98% or other extrastrong'acidu Such subsequent subjectionof Lima, cracked or uncracked oilin general to 98% or other extra strong acid is included in this thirdpart of the invention. v j

By taking the mixed stock' mentioned above iii-setting orth the secondpart of the .invention and distilling said stock in the presence ofcopper oxid mixed with or dissolved in the same, with separatecollection of the distillate which came over before and that which cameover after the distillate from the tail pipe 'ofthe condenser reached"439B I have :obtained two desulfurized products which I then dividedeach into two portions. I finished one lighter and one heavier portionfor burning oil (kerosene) b application to them separately of theMillnary sulfuric'acid and alkali treatment (using sulfuricacid of about66- B. atthe rate of six pounds to the barrel). Each of the other twoportions I treated separately with 98% sulfuric acid at about 38 F.initial, using ten pounds of 98% acid to the barrel of oil; and, afterrerunning, I gave each of the so treated portions a further lighttreatment with sul- .furic acid and alkali. Ialso steam stilled the elight end of said fraction; and the 98% or other extra strong acid canbe apperatures below about 60 F., as mentioned two light productsseparately. I thus ob tained four finished burning oil (kerosene)products of the following respective sulfur contents, namely:

Heav

- Heav 50/1000 per cent,

840/1000 per cent.

80/1000 per cent. The amelioration of the oil (especially the heavy end)by the subsequent treatment with 98% acid is plain; and I believe thatsimilar amelioration of the oil is obtainable with other extra strongacid as well as with 98%'acid. In obtainin this amelioration, itiwill beobserved that t e Whole cost of. the

98% or other-extra strong acid' is not to be charged a ainst it; sincesaid cost is partly offset by t e larger amountof acid of about 66.B.reriuired in the ordinary treatment given to t 1e first two products ofthis last table, as compared with the smaller amount of such acid usedin the light treatment given form of burnin after rerunning to the lasttwo products of said table. i i

S ecific reference herein above has been ma e to Lima oil only and to itonl in the oil (kerosene) distlllate or in the form 0 the yet lighter;naphtha. There are, however, oils not within the above given definitionof Lima oil which are so far analo ous thereto as to admit of usefuldesul ration in the form of burning (kerosene) distillate or. of the yetlighter naphtha. b means of 98% or other extra strong acid; a though byreason of their less content of refractory sulfur compounds or by reasonoft-he smoky character of their burningoil (kerosene) fraction, theirdesulfuration with 98% acid as above set' forth .would-not present allthe advantages which attend such de sulfuration of Limaoil as abovedefined.

For example, accordingKto my experience,

etroleum produced in ansas, when in the orm of the distillate yieldedbetween 300 F.

and 550 F. by the crude oil and prepared as aforesaid, responds to thefirst, third and fourth of the above mentioned tests; but it usuallyremains uncolored when clear plumrefracto sulfur compounds in the bateof sodium solution is added thereto...

In other words, in said pre ared form, it

usually fails to res 0nd to t e second'test mentioned and to't is testonly "of thefour. Such failure tends to show a less content of en'eralrun of o from the Kansas oil fields than in Lima oil as above defined.'Specialoils from Kansas wells have, however, in my experience res ondedin said prepared form to all four 0 the above ..mentioned tests;and'such special oils are consequently within the above definition ofLima oil.

Again, according to my experience, petroleum produced near Beaumont, inTexas, when in the form of the distillate yielded between 300 F. and 550F. by the crude oil andprepared as aforesaid, responds to the second,third and fourth of the above mentioned tests; but it is smoky. Whentested by the refractometer its refractive index is more than 1.4600. Inother words, in said prepared form, it fails to respond to the firsttest mentioned, and to this test only of the four. In making burning oil(kerosene) from such petroleum, it would, in my opinion, be preferableordiriarily to subject the burning oil (kerosene) distillate to 98% orother extra strong acid at a higher tempera ture than about 60 F. and inlargerproportion than even sixty 'ounds to the barrel in furation bmeans o f' 98% or other extra stron aci as herein-set forth. Beaumontpetro eum yields little naphtha; but that which is obtainable therefrom,and also the lighter non-smoking portion of its burning oil (kerosene).fractlon (cracked or uncracked, or a mixture of both), may well bedesulfurized in accordance with the present invention. Moreover, otheretroleum no doubt exists which is not wit the above definition of Limaoil, in that in case it should be tested in the said prepared form itwould not. respond to all four of theabove mentioned tests, but which isanalogous ,to Limaoil in that in such case it would respond to the thirdand fourthof said tests, or tothe fourth of them at least, with orwithout also responding to one or o'therof the first two tests (or toboth of these, if the prepared dis: tillatg should failto respond tosaidthird test). Such other'petroleum, with that from the Kansas oilfields (not within the definition of Lima oil) and that from the oilfields near Beaumont, in Texas, constitutes the,

analogous petroleumof the present SPGOIfiCfl-r tion. Further, I ;believethat Lima petroleum as above defined, and petroleum analogous thereto asaforesaid, can by means of 98% or'other'iextra strong acid bedesulfurized usefully ineother distillate forms (as well as in those ofburning oil and naphtha distillates) and evenin 'undistilled forms. I donot believe that Lima or analogous petroleum can' be desulfurizedthereby anywhere near so' advantageously in undistilled as in distillateforms; and consequently it is considered a special advantage andimprovement to desulfurize-the same in accordance with the presentinvention as distillates whenever distillation would not interfere withthe usefulnessfor their intended purposes of the products to beobtained.

As indicated above, I believe that more pounds of sulfur can be removedby-a given weight of 98% of other extra strong acid from lower boilingthan from higher boiling products; and hence special claims are made to'the desulfur'ation of Lima or analo ous petroleum in the form "ofdistillate lighter than .865 specific gravity (about 32 13.),

which expression (at least when applied to Lima oil) includes thedistillate next heavier than; burning oil (kerosene) as well as thelatter and naphtha. Hence also special claims are made to thedesulfuration of burning oil (kerosene) and naphtha distillatesseparatel or together, for the desulfuration of Whic distillatesthe-invention is primarily designed- I also believe that petroleumexists which is not within the above definitions of Lima and analogouspetroleum, but'which is sufi iciently related thereto to admit ofusefuldesulfurati'on in some form at least b means of 98% orother extrastrong aci although such desulfuration would robably not present alltheadvantages of a esulfuration of Lima (or evenof analogous) petroleum.The specified relationship for the urposes of this specification will beestabished for any petroleum by the fact that in some-form at least,although not in the form of distillate yielded betweenv 300 F. and 550F. by the crude oil, it responds (after the aforesaid preparation) tothe third and fourth, or to fourth at least, of said. tests,-

with or without responding also to oneor other or to both o f the firsttwo tests. Such petroleumforms part of the related oils of thepresentspecification. Lastly, I believe that h drocarbon oils derivedfrom sources other 't. an petroleum, say from maltha,asphalt,'bituminous shale, b1- tuminous coal, and so on, are (somerofthem at least) suific'iently related to Lima or analogous petroleum toadmit of useful desulfuration in some form at least by means of 98%or'other extra strong acid; although I. 7

would not venture to say that any desulfuration thereof, would presentall the advantages of a desulfuration-of Lima or analoetroleum by suchacid. The speclfied re ationship for the purposes of this speci ficationwill be sufliciently shown for any non-petroleum hydrocarbon oil by thefact that in some form at least, after theaforesaid reparationitrespondsto the third and fourt or to the fourth at least, of said tests,

with 'or' without responding also to one or other or to both of thefirst two tests. Such non-petroleum hydrocarbon oils form part-of therelated oils of the present specification. Some of them have aburningoil fraction which corres onds at least approximately inrefractive in ex, boiling point and viscosity,

new, useful andoriginal parts, improvements or combinations herein setforth. 7

The following'is .a descri tion of what'is considered the best mode 0carrying the invention into effect, takin by way ofexample, the Limacrudeo' from which the above mentioned uncracked stock has been obtainedand considering in order three cases, in the first of which cases allthe desulfurationof three different burning oil (kerosene) distillatesis effected by 98% or other extra strong acid without assistance fromany other material more energetic as a desulfurizer than sulfuric acidof about 66 B. in thesecond ofwhich cases the same three burning oil(kerosene) distillates are, respecwhich material is more energetic as adesulfu'rizer of Lima, oil than is sulfuric acid of about 66 B. and inthe third of which cases one (or more, if preferred). of thethreeburning oil (kerosene) distillates is'desulfurized by treatment with98%or other extra strong acid after it has beendesulfurized by anothermaterial also more energetic as a desulfurizer of Lima'oil than issulfuric'acid of about 66 B.

First case.The said Lima crude oil isv .from the-be ning of distillationuntil a specimen of distillate intercepted for the purpose at the tailpipe of the condenser has a gravity of about 41B. The receiver is thenIll) changed; and the distillation is continued with cracking, whichcommences in my X':

perience when the temperatureof the oil in the, still reachesflabout-620 F. It is carried on so long as it is considered'safe to do so.

All the distillate which comes over after the'distillatefrom the tailpipe of the condenser has attained a gravity of about 41 B. and" whichconstitutes the cracked oil (althou h containing uncracked roducts-also)is collected in one receiver. oil distillation is over this'cracked oilis transferred to an ordinary cheese box or cylinder still, and isdistilled in the ordinary way, with collection'of the distillate byitself in one reen the crude 1' ceiver until the oil from the tail pipeofthe condenser has a gravity of about 43 B. and with subsequentcollection of the distillate by itself in another receiver until the oilfrom the tail pi e of the condenser has a gravity of about 35 Theresiduum in the still can be disposed of as may be thought best. Threestocks to be desulfurized are thus obtained,

- namely, an uncracked Lima burning oil (kerosene) distillate, the lightend of the burnin oil (kerosene) fraction of Lima cracked oi and theheavy end of the same fraction. The first of these, being identical withthe above mentioned uncracked distillate, would represent the firstfifty per cent. of'the crude oil and would contain an amount of naphtha-e ual to' abouteleven per cent.'of the crude oil and would have asulfur content of 346/1000 per cent. The said light end would acid at aninitial temperature of about 38 F.,

' which canfbest be secured by running the stock on its way to theagitator through a continuous cooler, say, through pipes immersed inbrine, whichlatter is kept cold by an ice machine, or through chamberscontaining pipes filled with the refrigerating fluid of an ice machine,or through any other appropriate apparatus-forcontinuous cooling- Eachof t e so cooled stockis run by itself into an ordinary lead linedagitator until the latter is filled to the ordinary hei ht. The stock isnary then dried by means of so ric acid'of about 66 13., using the samesay at the rate of from 1/10 to 2/10 of a pound of the acid to thebarrelof stock. After the addition of "this small proportion of acid, the;mixture of acid and stock is agitated by blowing with ordiair for tenminutes, the mixture is allowed to settle for thirty minutes, and theacidsludge is then drawn off.

The stock, being now dry, is

sulfuration by 98% sulfuric acid.( or this pu ose, it is best to dividethe charge of the '98 0 acid into two or more batches, and,

' after adding each batch, except the last, to

the stock to agitate the mixture of acid and stock by blowing withordinary air for thirty minutes, then to allow to settle thirty minutes,and lastly to draw off the slud e before addindg the next batch of 98%ac'ri 1 After the a dition of the last batch, blow for thirty minutesand'allow to settle for an hour and then draw off the sludge. q

If the ob'ect is to obtain from the uncracked-stoc a'burning oil-(kerosene) prod-' uet containin not more than 1/20percent. of sulfur,sa1 stock would best be treated each barrel of said light end.

' preceding steam stilled b itself with co The resultin not exceeding10/1000 cracked and 19/ 1000 per cent. for the crackedread for detaken,he same I with two batches of 98% acid, each consisting often pounds ofsuch acid to each barrel of said uncracked stock.

, If the object is to obtain from the light end of the cracked oilv aburning oil (kerosene) product containing not more than 50/1000 er cent.of sulfur, said light end would best e treated with two batches of 98%acid,

each consisting of ten pounds of such acid to If the object is to obtainfrom the heavy end of the crackedoil a burning oil (kero-v sene) productcontaining not more than /1000 per cent of sulfur, said hea end wouldbest be treated with two batc esof 98% acid, each consistin of tenpounds of such acid to each barrel 0 said heavy end.

After each *stockhas been treated with 98% acid (twenty pounds to thebarrel, as' just mentioned), it ls'washed int-he manner usual in thesulfuric acid and alkali treatinent, first with water, then with causticsoda 1 e and finally with water. Each stock is t en rerun by itself andeach resulting tillate is given by itself a light treatment withsulfuric acid and alkali, using say three or four pounds of sulfuricacid. of about 66 -B or t e same weight of sludge from the treatmentwith 98% acid. The uncracked stock is then steam stilled by itself,until it has attained the desired fire test, the naphtha beingcollected. The light'end and the heavy end of the cracked oil are mixedandthe whole is steam stilled withcollection of the naphtha until theoil ha's' the I desired, fire test; or the light end can be ect'ionofnaphmixed withthe heavy end. products are. two ades 'of burning oilerosene) having a s tent of not more than 50/ 1000 per cent. for the thaand then uncracked and not more than 83/1000 per cent. for the crackedroduct andalso two grades of naphtha having a sulfur content, ofpercent. for the un roduct'. The heavy end of the buming oil action ofthe cracked oil, after separate re-.-

running and the subsequentseparate light treatment, should have a sulfurcontent of not more than 100/ 1000 per cent. The light end, after steamstilling and before mixture of the same with the heavy end, should haveasulfur content of not more-than 50/1000 per cent.

In rerunning either or both the naphtha htha out can be containingstocks, a nap tobe given byitselfa h ht treatment with sulfuric. acidand25150. a naphtha cutfor desulfuration apart from the urning oil(kerosene) d stillate-can be taken inthecrude oildistillation or in thecracked oil distillation. In such case, as-

suming that the same Lima crude oilas'before it taken. as an example,andthat'twor conadvantageous as any.'

desired) some other sulfuric p'riately stronger than that of about 66 innaphtha cuts are to be made, the two naphthe stocks may well represent,respectively,

the uncracked about eleven and the cracked about one per cent. of thecrude oil. In de- 5 sulfurizing them with 98% sulfuric acid, the

0 of naphtha should be desired, the two na h the cuts can be mixed witheach other efore desulfuration. 4

Instead of changing the receivers and stopping the distillations at theoints mentioned 5 the receivers can be change and the-distillati0ns, erany of them, sto ped at any desired,

points; although under t e assumed con ditions the points indicated arein general considered the most advanta 'eous, or at least as ima crudeoil as above defined will vary both in its percentage of hydrocarbons ofdifferent boiling points, 1n its 'sulfur content, and I believe also inthe kinds of its constituents; and crude petro- 5 leums analogous'toLima oil are likely to vary yet more in each of these respects.

In the first part of this specification sufficient directions have beengiven to enable the proportion of 98% sulfuric acid to be adjusted tothe varying conditions, only it seems well to say here that, judgingfrom my experience, whenever a crude etroleum yields an uncrackedburning oil kerosene) distillate a specimen of which has a sulfurcontent ofless than 2/10 per cent. after treatment with sulfuric acidand alkali, using sulfuric acid of about 66 B. at the rate of twentyounds to the barrel, and especially if it furt er fails to respondv tothe second of the before mentioned tests, the sulfur corrtent of suchuncracked distillate can be nee duced to or below 1/20 per cent. by theuse of less than twenty pounds of 98% sulfuric acid at about 38 F.initial. For using (if acid a roplace of 98% acid, the foregoingdirections it IS believed will suffice.

Instead of initially cooling the stocks (or 0 any of them) to about38'F., they couldbe cooled to a lower temperature; or they need not becooled so low; only it is believed that there would be a disadvantagerather than advantage in departing from about 38 F. initial. It is notconsidered advantageous to cool either the'98% or other extra strongacid appliedto the oil or the air fora itating the mixture; nor is itconsidered advantageeus to restrain the rise of temperature whichnaturally follows the reaction of the said acid on the sulfur compoundsand other constituents of the oil; things may be done, the onlyobjection to them being on the score of unnecessary ex- 5 pense.

- said first case. the light end of the cracked oil are then separatelydesulfurized in any known or suitable I butany or all of these Secondcase-The said Limav oil is distilled at first in the ordinary way andthen with cracking, the uncracked distillate and the cracked oil beingcollected in separate receivers, asiin the first case. The cracked oilis distilled with change of receiver, also as in The uncrackeddistillate and manner by some known or suitable material other than 98%or other extra strong acid,

which material is a more energetic desulfur izer of Lima oil than'issulfuric acid of about 66 B., say, with copper oxid mixed with ordissolved in the oil to be desulfurized while the latter is undergoingdistillation; and the heavjy end of the cracked oil is desulfurized with98% sulfuric acid applied inthe manner and roportion abovesetforth indescribing the st ca'se.- The uncracked distillate and the light end ofthe cracked oil are sepa-- rately treated in the ordinary manner wlthsulfuric acid and alkali (with use, say, of six pounds of sulfuric acidof about 66 B. to the arrel of oil treated). As in the first case, theheavy end, after treatment with 98% sulfuric acid, is rerun; and thedistillate obtained in the rerunning is finished by a light treatmentwith sulfuric acid and alkali; The

heavy end and the light end of the cracked oil are then mixed together;and the mix ture is steam stilled to obtain the desulfurized naptha andalso to givea proper fire test to the burning oil (kerosene). 'Ihedesulfurized uncracked oil is steam stilled for the same purposes. Thelight end of the cracked oil could be steam stilled before admixturewith the heavy end; and subsequent steam stilling could then bedispensed with. Naphtha cuts to be desulfurized separately can be takenin the ordinary distillation. of the crude oil and the cracked oil,respectively. -And such naphtha cuts can be made and the naphthadistillatesmixed before desulfuration, if-only one grade of ma hthashould be desired. The receivers can e changed and the distillations (orany of t hem).stopped at any desired points. In place of 98% acid}'other extra strong acid can be used; and the pro ortion of the acidused can be adjusted to t e condition of the stock to be treated; andthe temperature of treatment therewith can be varied, all as hereinabove set forth.

Third cds'e.-The said Lima crude. oil is distilledat first in theordinary we; and then;

with cracking, the uncracked and the cracked distillate being collectedin separate receivers,-

as in the first case. a The cracked oil is distilled without change ofreceiver; and the distillation is stopped when the distillate fromthetail pipe of the condenser has a grav ity of about 35 B., as in thefirst case. The uncracked distillate and theentire cracked oildistillate are then se arately desulfurized inany knownor suita le Way,more especially, but not exclusively, by means of an appropriatelyenergetic metal, metallic oxid or metallic salt (or of one or more ofthem),

stopped when such distillate has a gravity of about 35 B., so as toobtain as near as may be the samelight and heavy ends of said burningoil fraction of said Lima cracked oil (cracked oruncracke 15 which wereobtained in the first case. The desulfurized uncracked distillate andthe de sulfurized light end are then separately given each of them anordina treatment with suliuric acid and alkali (us ng say six pounds ofsulfuric acid of about 66 3., to the barrel of stock treated). Thedesulfurized heavy end,

- in order still further todesulfurize it, is 've'n a treatment with 98%sulfuric acid-at a out: 38 F. initial and is rerun and is then finishedb a light treatment with sulfuric acid a and al ali, all as set forthfor the corresponding heavy endin-the first case, onl instead of theproportion of 98% acid t ere given it is now necessary to use aproportion of only ten. pounds of acid to the barrel ofheavy end, inorder to obtain thesame with a content of sulfur even below that givenin the description of the first case; and, unless a still lower sulfurcontent should be desired,-

this smaller pro ortion of 98% acid would best be used. t would best beapplied in two equal batches. The light end and the heavy end are mixedwith each other; and themixture is steam stilled to obtain thedesulfurized naphtha and also to raise the fire test of th finishedburning pil (kerosene). The latter, (according to my experience) may beex cted to contain about 73/1000 ercent. 0 sulfur, its'light end havinga sulur content of about 60/1000 percent. and its heavy end about 80/1000 per cent. The uncracked .oil is steam stilled to recover thenaphtha therefrom and to raise the fire test of the finished burning oil(kerosene). The

150 light steam stilled and then mixed with the heavy pend, dispensingwith steam stilling after the mixture. T If the percentage of sulfur ineither the light end of the cracked o'il orin the'uncracked distillateshould be regarded as too hi h, either or each of them could be treatewith 98% sulphur at about 38F. and rerun and then finished by a lighttreatment treatment of them with sulphuric acid and alkali being bestomitted.

Se arat-e naphtha cuts (to be separately desu furized) can be taken inthe ordinary '65 distillation of the crude oil and in the. disend of thecracked oil could first be acid usedcan be adjusted to the condition.

in oil distillation,

.. pleted tillation of the cracked oil, respectively. And suchnaphtha'cut's could be'made and the naphtha distillates mixed beforede-- sulfuration, if only one grade of naphtha should .-be desired. The.receiverscan be chan ed and thedistillations (or any of them stopped atany desired points. place of 98% sulfuric acid, other'extra strong acidcan be used; and the proportion .of the of the'stockto be treated andthe temperature of treatment therewith can'be varied, all as hereinabove'set forth. In order to have articular distillates in adesulfurize'd state, it is not necessary first to obtain and n then todesulfurize them; they can be obtained first in a desulfurized state.For example, in carrying. out the present invention in accordance'withsaid third case, the uncracked burning oil (kerosene) distillate can beobtained in a desulfurized state by efiecte the requisite desulfurationin the crude j the vapors from the crude oil being passed .over copperoxid after saidvapors have been iven off from the body of the crude oil.an while they are on their way to the condenser, and the receiver beinchanged whenv the oil from the tail pipeo the condenser. attainsagravity of, about 41 3.; and. the two ends of the burning oil(kerosene) .fraction of the cracked oil can be obtained in adesulfurized condition by effect the desulfuration either in the crude 0.or in the cracked oil distillation, the vapors being passed .overcopper oxid after said va ors have been given ofi from the brig? o thecrude oil or of the crackedoil w e they are on their way to thecondenser and the receiver bei'n chan ed in the cracke 10 oildistillation when t e oil cm the tail ipe of the condenserattainsa'gravity of. 9. out 43- B. For effecting the desulfuration of bothuncracked and cracked distillate in the crude oil distillation, thepassage of vapors from the crude oil over the copper oxid 'would firstbe carried on until the collection of the uncracked distillate should becomand thereupon the receiver would be changed and the passage of thevapors from the crude oil over the copper oxid would be continued untilall the cracked oil shouldbe received. desulfurized crackedoil wouldthen be'dis'tillated with change of receiver when the oil from the tailpipe of the condenser attains a gravity of about 43 B. and with stoppageof the distillation when it reaches about 35 3, so as to separate theflight end-and the'heavy end from each other,

60 with sulphuric acid and alkali. the ordinary :as well as. fromstillheavier hydro-carbons. 1i desulfuration of the unthe crude oildistillation 4 .For efiecting' the and thatof the light and heavy endsin the cracked oil distillation, the vapors from the crudeoilhwouldrbest be passed over the 11 cripper 'oxid only until theuncracked disti ate should'be collected; and thereupon the receiverwould be changed and the vapors from the crude oil be passed directly tothe condenser until all the cracked oil'should be received- This-latterwould then be distilled with passage of the vapors therefrom over copperoxid on their way to the condenser, andwith change of receiver when theoil from the tail fpipe of the condenser attains a gravity 0 about 4:3B., the distillation being stopped when a gravity of about 35 B..is'attamed bysuch oil. The uncracked distillate and the light end ofthe cracked. oil (in whichever way obtained)- could then be given (eachof them separately) a treatment with sulfuric acid and alkali. The heavend (in whichever way obtained) could be rther desulfuriaed at about/38F. initialby' means of 98%-sulfuric acid, ten

pounds to .the *barrel, with subsequent rerunning, followed by a'liglhttreatm'ntwith sulfuric acid and alkali. he un'cracked distillate couldbe steam stilled; and the light end of the cracked oil could be mixed wth the'heavy end thereof and the whole steam stilled, or the light =endcould be steam stilled and then be mixed with the heavy end. i

If it should be desired'to make only one grade of burning oil'(kerosene), to be composed of both the cracked and uncracked dis-'tillates, "it will, nevertheless be' more advantageous; ordinarily tocracked oil separately. from crackedioil (at least'whentheir-desulfuration is eflected by means of 98% or other extrastrong-acid) aswell as to desulfurize the heavy'end of the burning oilfraction of the cracked oil by, such acid after separation of the lightand heavy ends from each. other but if,the advantages of separatedesulfuration should the same would always be treate in aform.

not bedesired, cracked and'uncrackedioils can be desulfurized to etherand the: heavy end of the cracked oil can be desulfurized withoutprevious separation of the light and heayy endszthereof from each other.

, *With respect to the desulfuration by means of 98% or other extrastron acid bf. petroleum and other hydrocarbon o' relatedas aforesaid-toLima or analogous etroleum,

in which, after the aforesaid pre aration,

they, respectively, respond to the t 'rd and fourth, or to the fourth atleast, of the above mentioned tests. It will be' found mostadvantageous, as I "Believe, to'cool the oil to be -desulfurized toabout 38 F. by rumiing the, same on its,way to the'agitator through acontinuous cooler; and to treat itat such initial temperature with 98%or other extra strong acid in the manner above described,-

tote the ro ortion of acid to oil be adjusted esulfuration to be effect5 thereby. The best proportion can be determined after the mode'abovedescribed, orotherwise, if

esulfurize unpre preferred. The oil, after finall drawin off the sludge,would be rerun; an the resu ting distillate would be given a lighttreatment' ,;cases at least I believe that it will be advantageous thusto desulfurize said heavyend with 98% or other extra stro acid, after itshallhave been desulfurizedwit another material, as cop er -oxid, more'energetic as a '.80 desulfurizer o Limapetroleum than is sulfuricacid ofabout 66 B. i

The modifications set forth above are not all which can be made; theyaregiven by way of example; and the statement of them islnot to beconstrued as an intention to exclude others; and. generally it may besaid that each of the im rovements composin the inventioiris inten ed tobe secured for. a the uses to which it canbe applied, with or withoutmodificatio 1 In the hereinafter written claims. the followingexpressions have, respectively, the following meanings wherevertheyoccur namely: 7

- Lima or analogous petroleum or related oil includes:

First. Petroleum within the above definition of Lima oil, that is tosay, petroleum which, in the form of the distillate yielded 10". between300 F. and 550 F. by the crude oil and pre ared. as aforesaid, respondsto all four of. t 'e above mentioned tests;

Second. Petroleum whichisnotwithin the i above definition of Limaoil,'in that in theme form of said distillate re ared as aforesaid itdoes not respond to a Lima oil does, but which is, nevertheless,

our ofsaid tests as analogous to the latter in'that in said-,form itresponds to thethird and fourth of said tests, or to the fourth of themat least, with or without also responding to one or other of the-firsttwo tests ,(or to both of these, if the ared distillate should fail torespond to sai third test) distillate yielded between 300 F. and 550 F.by the crude oil .and prepared as aforesaid fails to respond to saidfourth test, but which,

nevertheless, is related to Lima hr analogous 12,0 petroleum,in.that insome 'form at least,

-after the aforesaid preparation,'it does respond to the third andfourth of the above mentioned tests, orto the fourth at least of them,with or without also responding to one 12 or other or to both ofthe'first two tests; and

Fourth. Hydrocarbon oils which are derived from sources other thanpetroleum and which cannot, therefore, be re arded as petroleum in anyform, butwhic are, never- .115 Third' Petroleum-which in thefortn of. i

- sulfuric acid containing not more than about anhg'drid; but by ex--four per cent. sulfuric tension it means also, on t e one hand, non- 15-fuming sulfuric acid of less than about 96% sulfuric monoh drate, whileyet enough strongerthan su uric acid of about 66 B. to have a usefuldesulfurizing effect on Lima or analo ous pptroleum'or related oil notpossesse by t e latter acid, and, 'on the other hand, fuming sulfuricacid .of more than about four. er cent. sulfuric anhydrid', as well asen ric anhydrid (100%) 'itself. Non-fu'mm sulfuric acid of about 98%sulfuric mono ydrate is considered to. have the Y greatest ratio ofdesulfurizing activity to cost andconsequently to be the mostadvantageous to use as a desulfurizer of Lima or analogous petroleum;but non-fuming acids of less than about 98% and not less than about 96%sulfuric monohydrate haye so nearly the same desulfurizing efiect as 98%acid at sligllgtly less cost and fumin acids of all strengt up to notmore than a but four per cent. sulfuric anhydrid-cost so little morethan 98% acid with slightly" reater desulfurizing effect that I class tem all with;

98% acid as included in the sulfuric 'acid' stronger thanthat ofeabout66 B. which it Which is sulfur bearing as ecified means that the stock,the diet ate, the cracked oil, or the heavy end of cracked oil of theburning oil fraction referred to b said expression responds, aftertheaforesai preparation, to the third and fourth, or to the fourth isprimarily intended to employ.

. at least, of the before mentioned tests. It-

may also-respond to one or other or to both of the first and second ofsaid tests, according to the case; or it may fail to respond to eitherof them. The word stock merely means the oil to be desulfurized. Itincludes undistilled oils whose desulfuration may be desired, as wellasall sorts of distillates.

Tein eratu're lower as specified than about F. initial primarily meansatemperature not higher than about 44"v F. initial; but by extension itmeans also, first, a temperature higher than about 44 F. initial and nothigher 60 than about 50F. initial, and, secondly, a

tem erature higher thanabout 50 F. and not her-than abeut 56 F. initial.1 This to lie-artificially produced.

ticular rate. temperatureisexpresslysaid'in certainclaimsf 0 Thoseclaims 6 whichmention a temperature lower. as specie fied than about 60F. and do not contain the words artificially produced include such lowertemperature as specified when produced I otherwise as well as whenproduced artificially'. For example,-in winter a tank of oil mightnaturally have a tem erature lower as specified than about 60 mostadvantageous temperature, considering expense foruartificial cooling inconnection with saving of acid, is about 38 F. initial; but at temeratures below about 38 F. initial the cost 0 cooling may be so littlemore and-at temperatures above about 38 F. initial to and includingabout 44$ F. initial the saving in-acid is so little less than at about38 F. initial that I class them all with this last temperature asincluded in the temperature below about 60 F. initial, which it isprimarily intended to employ. It will be observed that in a number ofclaims this temperature exression does not occur.

Distillate lighter as specified than .865 specific gravili]? meansprimarily distillate "which is mai or wholly com osed of hydrocarbonsnot too heavy nor toolight to serve usefully as constituents of burningoil; but by extension it means also in the first place distillate whichis mainly orwhollycomposed of hydrocarbons too light to serve usefullyas constituents of burning oil, and, secondly, distillate which ismainly or wholly composed of hydrocarbons too heavy for such service,but not so heavy asto have a specific gravity of Rate not exceedingabout sixty pounds to the barrel as specified means primarily aproportion of not more than about thirty pounds of acid to theforty-gallon barrel of the. stock .to be desulfurized, yet sufficient toproduce a useful desulfuratlon; but by extension it means also, first, apro ortion-exceeding about thirt and not excee ing about forty pounds ofacid to the barrel ofstock, and, secondly, a proportion exceeding aboutfort and not excee 'ng. about fift pounds of acldto the bar- I rel ofstock and, t 'rdly, a pro ortion exceeding about'fifty and not excee mgabout sixty oundsof acid to the barrel of stock. With ess than aboutthirty pounds of 98% acid (namely, with about twenty pounds) to the madeclaims which donot specify any parlit-end means primarily hydrocarbons'eu'itabe forbu o Withboiling ointshelldw-aboutSOO? F. utitmeansalsoYexten:

merely by standing exposed to the cold weather. The

three successively higher proportlons in the extended meanof this rateexpression; and I have alsopoints between about 500 'sion the lighterportion generally of a series of hydrocarbons capable of servingusefully as constituents of burning oi-l.

Heavy end means primarily hydrocarbons suitable for burnin oil 'with'boiling and about 600 F., both inclusive; but it means also by extensionthe heavier portion generally of a series of hydrocarbons capable ofserving as constituents of burning oil. Stock which consists of heavyend is composed Wholly or mainly, or at the least in large part, of suchheavier hydrocarbons. gous petroleum or related oil can be desul furizedin the form of said heavy end with or without previously separating theheavy and light ends from each other; and such separa tion, whenefl'ected, may be nearly or quite com lete or in large part only, so asto obtain for dhsulfuration a distillate free from said light end, ornearly so, or one deprived in large part only of said light end. I

Material as specified other than,v said stronger acid, which material ismore energetic as a desulfurizer of Lima petroleum than is sulfuric acidof about 66 B. means primarily one or more oxids of metals recifpitableinacid solution by hydrogen su d,

which copper oxid and lead oxids are exainples; but it means also byextension, fiIStyOIiG or more of the metals in general, oxids in generalof metals not preci itable in acid solution by hydrogen sulfid, anmetallic salts in general, known as desulfurizersof Lima petroleum orsuitable for such'nse either when mixed with or dissolved in Limafurized oil undergoing distillation or when to vapors of Lima oil afterthey havebeen given off, or in botlusuch ways, and, secondly, any otherknown or suitable material except sulfuric acid stronger than that ofabout 66 B. for de riving Lima vpetroleum of sulfur compoun s unremovedtherefrom by said sulfuric acid of about 66 B.

In specifying in certain claims that the hea end of cracked oil of theburning oil fraction is to be desulfurized after separation of the lightand heavy ends from each other and is then to be rerun or distilled, itwill be.

understood that the heavy end is most ad"- vantageousl rerun ordistilled apart from the light em but that this is not necessarily so;since the separately desulfurized heavy end could be rerun or distilledafter a mixture of the same and the light end with each otherfollowingupon "the se arate desulfuration of the heavy end; and both modes ofrerunning or distilling the separately desuleluded within the scopeofsaid claims. So likewise in specifying in certain claims that the saidhea end is .to be subjected to suecessive desul rrizing operations inthe later of which the; said heavy end is desillfurized- Lima oranaloexposed I mixed with light end ends (cracked or uncracked) ofsuitably low heavy end are intended to be in-.

after separation of the light and heavy ends from each other, theearlier desulfuration could be made with or without previous separationof the light and heavy ends from each other; and both modes are intendedto be included within the scope of these claims.

Further in specifying in certain claims that the light end and theheavy'end are to be mixed, it is not intended to specify .the point inthe procedure at which the mixing is to be effected further than it isto be after a desulfurizing treatment of the heavy end following upon aseparation of the light and heavy ends from each other.

Non-smoking cracked oil of the burning oil fraction means a cracked oilwhich fairly re resents said burning oil fractionas a wlible and which,after the aforesaid preparation, has a refractive index sufficientlybelow 1.4600 to indicate anon-smoking oil. Such a representative oil isobtainable by distilling the cracked oil in a laboratory flask providedwith a thermometer as above mentioned and collecting the distillatewhich 'comes over between 300 F. .and 550 F.- If

the heavy and light ends of such non-smoking cracked oil shouldbeseparated from each other, and if the heavy end should then be tested byitself, after the aforesaid preparation, it might or might not have arefractive index below 1.4600.

Obtaining from Lima or troleum or related oil bur ized by means ofsulfuric acid stronger as s ecified than that, of about 66 B. means obtaining'in art at least from Lima or analogous etroleum or so desulrized 'at least in-part. of cracked oil of the burning oil analo ouse-011 esu r- Heavy end fraction ebrelated oil burning oil tained from Limaor analogous petroleum or relatedoil and desulfurized by means of saidstronger acid, with or without assistance from other materials, might,for exam le, be

or with light andeavy sulfur content obtainedl'also from Lima oranalogous petroleum or related oil; or it might be mixed with light endor light and heavy ends (cracked or uncracked) of suitably low sulfurcontent obtained from any other petroleum or hydrocarbon oil.

Claim 26 s ecifies a desulfuration by means of anot er materialipreviousto the desulfuration withsaid stronger acid; and claim 27 does not sospecify; but claim 27 does not exclude such previous desulfuration; andneither of the. claims excludes a subsequent destlfuration; nor doeseither claim exclude a desulfuration of any kind in addition to thatspecified therein. None of the twenty seven claims, in fact, excludes a*desulfuration of any kind in addition to that s ecified therein; nordoes any claim ex- 0 ude the admixture' of other petroleum or lower as secified t an about 60 hydrocarbon oil with the Lima or analogouspetroleum or related oil to be desulfurized as therein specified.-

I claim as m invention or discove 1. In desu'l rizing Lima or ana ogousetroleumor related oil b means of sul- 'ric acid stronger asspecifi edthan that of about 66 B., the improvement consisting in subjecting thesame, in the form of stock which is sulfur bearingas specified, to theaction of said stron er acid at a tem e'rature initial, substantia y asdescribed.

2. In desulfurizing Lima or analogous petroleum or related oil by meansof sulfuric I jecting the same, in the form ofdistillate which is sulfurbearing as specified and also lighter as specified than .865specific'gravity, to the action of said stronger acid at a rate i notexceeding about sixty pounds to the barrel as specified and at atemperature lower as s ecified than about 60 F. initial, substantlallyas described.

4. In desulfurizing Lima or analogous petroleum orrelated oil by meansof sulfuric v acid stronger as specified than that of about 66 B., theimprovement consisting in subjecting the same, in'the form of stockwhichis sulfur bearing as specified, to the action of said stronger acidat a ma not exceeding about sixty pounds to the barrel as specifie andat. a tenliperatuiie lower as specified than about 60 initial,substantially as" described.

' 5. In desulfurizing Lima or analogous pe-' troleum or related oil bmeans of sulfuric acid stronger as specific than thatof about 66 B., theimprovement consisting in subectmg the same, in the form of stock whichis sulfur bearing as specified, to the action of said stronger acid at arate designedly adjusted with respect to the removal of sulfur and at atem erature lower as specified than about 60 initial, substantially asdescribed. i

6. In desulfurizing Lima or analogous petroleum or related oil b meansof sulfuric acid stronger as specific than that of about 66 B., theimprovement consisting in subjecting the same, in the form of burningoil distillatewhich is sulfur bearing as specified, to: the action.ofsaid. stronger acid at a temperature lower as specified'than about60.9 F.

initial and at a rate not exceeding sixty pounds to the barrel as secified and not less than sufficient, when f0 owed by rerunning and asubse uent. treatment with sulfuric acid and alkali, to reduce thesulfur content to a percentage admissible in marketable burning oil, sustantially as described.

7. In desulfurizing Lima or analogous petroleum or related .oil by meansof sulfuric acid stronger as specified han that of about jecting thesanie, in the form of distillate which is sulfur bearing as specifiedand also lighter as specified than about .865 specific gravity, to theaction of said stron er acid at a temperature lower as specified t 1anabout 60 F. initial, and subsequently rerunning said distillate andgiving to the rerun oil a treatment with sulfuric acid and alkali,substantially as described.

, 8. In desulfurizing Lima or analogous petroleum or related oil bymeans of sulfuric acid stronger as specified than that of about 66 B.the improvement consisting in cooling a stream of the Lima or analogouspetroleum or related oil, in the form of stock which is sulfur bearingas specified, to a temperature lower as specified than about 60 F.

y extracting the heat from the flowing oil by means of a cooling mediumwhich is se arated therefrom by heat conducting walls, subjecting the socooled oilto the action of said stronger acid at such artificiallroduced tem erature' lower as specific t an about 60 F and subsequentlydistilling the so treated oil and giving the resulting distillate atreatment with sulfuric acid and alkali, substantially as described.

, 9. In desulfurizing Lima or analogous petroleum or related oil b meansof sulfuric acid stronger as specific than that of about 66 B., theimprovement consisting in subjecting the same, in the form of stockwhich is sulfur bearing as specified, to the action of said strongeracid at an artificially produced 60 initia substantially as described.

1'0.. In desulfuriz' Lima or analogous pe troleum or related'oilgb meansof sulfuric acid stronger as specific than that of about jectingthe-same, in the form of distillate which is sulfur bearing as specifiedand also lighter'as specified than .865 specific gravity; to the actionof said stronger acid at an artificiall produced tem rature lower asspeci fied than about 60 initial, substantially as described.

1 1. In desulfuriz' troleum or related oil b means of sulfuric acidstronger as specific than that of about 66 B., the improvementconsisting in subjecting the same, in the form of distillate [which issulfur bearing as specified and also lighter as specified than .865specific gravity,

66 B., the improvement consisting in subtemgeraturelglower as specifiedthan about I 66 B., the improvementconsisting in sub-' Lima or analogouspe- I 12. In desulfurizing Lima or analogouspetroleum or related 011 bymeans of sulfuric acid stronger as specified than that of about 66 B.,the improvement consisting in subjecting the same", in the form of stockwhich is sulfur bearing .as specified, to the action of' said strongeracid at a rate not exceeding about sixty pounds to the barrel asspecified and at an artificially produced temperature lower as s ecifiedthan about FE initial, substantia ly as described.

13. In desulfurizing petroleum or related oil by means of sul ric acidstronger as specified than that of about 66B., theimprovement consistingin sub jecting the same, the form of stock which is sulfur. bearing asspecified and consists of the heavy end of cracked oil of the burningoil fraction after separation of the light and heavy ends from eachother, to the action of said stron er acid at a temperature lower asspecified t an about 60F. initial,'substan-.

. tially as described.

14. In desulfurizing Lima or analo ous petroleum or related oil by meansof sul ric acid stronger as specified than that of about 66 3, theimprovement consisting in subjecting the'same, in the form of stockwhich is sulfur bearing asspecified and consists of the heavy end ofnon-smoking cracked oil of the burning oil fraction after separation ofthe light and heavy ends from each other, to.

the action of said stronger acid, substantially as described.

16. In desulfurizing Lima or analogous petroleum or related oil by meansof sulfuric acid stronger as specified than thatof about.

66B., the improvement consisting in subjecting the same, in the form ofstock which is sulfur bearing as specified and consists of the heavy andofcracked oil of the burnin oil fraction after separation of the lightan heavy ends from each other, to the action of said stronger acid at arate not exceeding about sixt pounds to the barrel asspecified,substantia y as described.

17. In desulfurizing Lima or analogous 'jecting the same, Lima or analoous- 1 of sulfur,

petroleum or related oil by means of sulfuric acid stronger as specifiedthan that of about 66B., the improvement consisting in subjecting thesame, in the form of stock which is sulfur hearing as specified andconsists of the heavy end of non-smoking cracked oil of the burning oilfraction after separation of the light and heavy ends from each other,to the action of said stronger acid, and subsequently rerunning saidheavy end and giving to the rerun oil a treatment with sulfuric acid andalkali, substantially as described.

18.. In desulfurizin Lima or analo ous petroleum or related 011 by meansof sul ric acid stronger as specified than that of about 66B., theimprovement consistin in subin the form of the heavy end of cracked oilof the burning oil fraction, Which heavy end is sulfur bearing asspecified, to successive desulfurizing operations, in the lateratleastof which the said heavy end is desulfurized after separation ofthe li ht and heavy ends from each other, the ear ier desulfurationbeing effected by means of material as specified other than saidstronger acid, whic material is more energetic as a desulfurizer of Limapetroleum than is sulfuric acid of about 66 B., and the later beingeffected by means of said stronger acid, substantially as described. 19.In desulfurizing Lima or analogous petroleum or related 011 by means ofsulfuric acid stronger as specified than that of about 66 B.,theimprovement consistin in subjectin the same, in the form of t e heavyend o cracked oil of the burning oil fraction, which heavy end is sulfurbearing as specified, to desulfura-tion by means of materialas-specified other said stronger acid, which material is more energeticas a desulfurizer of Lima petroleum than is sulfuric acid of about 66B., and subsequently to further desulfuration b means of said strongeracid, substantial y as described.

20. In desulfurizin Lima or analogplps petroleum or related 011 by meansof 'sul '0 acid stronger as specified than that of about 66 B., theimprovement consisting in sub- .jecting the same, in the form of crackedoil which is sulfur bearing as specified, to desulfuration by means ofmaterial as specified other than said stronger acid, which .material ismore energetic as a desulfurizer of Lima petroleum than is sulfuric acidof about 66 B. ,and subsequent] to further desulfuration by meansof saistronger acid, substantially as described.

21. In desulfurizing Lima or. analo ous petroleum or related oil bymeans of sul uric acid stronger as specified than that of about 66 B.,the improvement consisting in subjecting the same, in the form of stockwhich is sulfur bearing as specified, to desulfurization by means ofmaterial as s ecified other than said stronger acid, 'whic materialistion by means of material as s ecified other than said stronger acid,whic material is more energetic as a desulfurizer ofLima petroleum thanis sulfuric acid of about 66 Bl, and s'ubseguently to" furtherdesulfuration by means 0 said stronger acid, distilling the sodesulfurized oil, and. giving to the resultin distill-ate a treatmentwith sulfuric acid an alkali, substantially as described. I

23. In desulfurizing Lima or analogous petroleum or related 011 by meansof sulfuric acid stronger as specified than that of about 66 13., theimprovement consisting in subjectin the same, in the form of stock whichis sul bearing as specified, to desulfuration by means of material as secified other than said stronger acid, Whic material is more, energeticas a desulfurizer of Lima petroleum than is sulfuric acid 9f about 665., and subsequentl to further desulfuration by means of sai strongeracid at a rate de- 1 edly adjusted with respect to the removal sulfursubstantially as described.

24. In desulfuriaing Lima or analo ous petroleum or related oil'b'ymeans of sul ic acid stronger as specified than that of about 66 3., theimprovement consisting in sub jectii g the same, inthe form ofstockwhich is s bearing as specified, to desulfuration b means of material ass ecified other than said stronger acid, 'whic material is moreenergetic as a desulfurizer of Lima pze troleum than is sulfuric acid ofabout 66 and subs'equentl to further desulfuration b means of saistronger acid at a rate designedly adjusted 'with respect. to the reacidstronger as'specified than that of about than said strongera'cid, whicjectirlijguthe same, in the form of stock which is en tion by means-ofmaterial as specified other material is more energetic as a desulfuriz'er of Limapetroleum than is sulfuric acid of about 6613.

r bearing as specified,'to desulfura-- and subsequently to furtherdesulfuration by means of said stronger acid at a temperatureloweras'splecifiedthanabout F. initial,

substantia y-as described.

26. In obtaining from Limaor analo ous petroleum or from relatedoil'burning oi de-. sulfurized by fneans of, sulfuric acid strongerasspecified than that of aboutf66 B., the

improvementconsisting .in subjecting su'ch Lima or analogous petroleumor related oil,

in the form of the heavy end of cracked oil of the burning oilfra'ction, which heavy end is sulfur bearing as specified, to successivedesulfurizing operations performed the earlier by means .of-materialas'specified other than said stronger acid, which material is more.

energetic as a desulfurizer-of Lima petroleum than is sulfuric acidlofabout 66 B. ,'and the later by means of said stronger acid,'andthe laterat least ofsaidoperations being performed after separation of the lightand heavy ends from each other-, and-mixing the so desulfurized heavyand with light end of suitably low sulfur contents, substantially asdescribed. 1

.27. In obtaining-from Lima or analo ous petroleum or from related oilburning oildee,

sulfurized by means of sulfuric acid stronger as specified than that ofabout 66 3., the improvement consisting in subjecting such Lima oranalogous petroleum or related oil; in theform of the heavy end ofcracked oil of the burning oilfraction, which heavy and is sulfurbearing as specified, .to the actionjof said stronger acid afterseparation of the light and heavy'e'nds from each other, and

' mixing the so dcsulfurized heavy end with light and of suitably lowsulfur contents,sub-

stanti'ally as described.

In testimony whereof I afix-my signature, in presence 'of twosubscribingwitnesses. I I

. CLARENCE I. ROBINSGN. Witnesses: v

' J. EL ,EoeLEsroN,

CHARLES 'G.' BLACK.

It is hereby certified that in Letters Patent No. 910,584, grantedJanuary 26, 1909, upon the application of Clarence L Robinson, of WestNew Brighton, New York, for an improvement in Desu1furizing Lima orAnalogous Petroleum and Related Oils,

errors appear in the printed specification requiring correction, asfollows: In line 12,

page 8, 840/ 1000 per cent should read 40;1000 per cent; line 13, page0, the word of, second occurrence, should read or, and in line 5, page14, the word or/ second occurrence, should read at; and that the saidLetters Patent should be read with these corrections therein that thesame may conform to the record of the case in the Patent Oflice. I

Signed and sealed this 23rd day of February, A. D., 1 909.

'[SEAL] c. c. BILLINGS,

Acting Commissioner of Patents.

